Phentolamine

Generic name: Phentolamine mesylate
Dosage form: injection
Drug class:Miscellaneous cardiovascular agents

Medically reviewed by Drugs.com. Last updated on Dec 1, 2021.

Phentolamine Description

Phentolamine Mesylate for Injection, USP is an antihypertensive, available in vials for intravenous and intramuscular administration. Each vial contains Phentolamine mesylate, USP, 5 mg, and mannitol USP, 25 mg, in sterile, lyophilized form.

Phentolamine Mesylate, USP is 4,5-dihydro-2-[N-(m-hydroxyphenyl)-N-(p-methylphenyl) aminomethyl]-1H-imidazole 1:1 methanesulfonate, and its structural formula is

Phentolamine mesylate, USP is a white or off-white, odorless crystalline powder with a molecular weight of 377.46. Its solutions are acid to litmus. It is freely soluble in water and in alcohol, and slightly soluble in chloroform. It melts at about 178°C.

Phentolamine - Clinical Pharmacology

Phentolamine Mesylate for Injection, USP produces an alpha-adrenergic block of relatively short duration. It also has direct, but less marked, positive inotropic and chronotropic effects on cardiac muscle and vasodilator effects on vascular smooth muscle.

Phentolamine Mesylate for Injection, USP has a half-life in the blood of 19 minutes following intravenous administration. Approximately 13% of a single intravenous dose appears in the urine as unchanged drug.

Indications and Usage for Phentolamine

Phentolamine Mesylate for Injection, USP is indicated for the prevention or control of hypertensive episodes that may occur in a patient with pheochromocytoma as a result of stress or manipulation during preoperative preparation and surgical excision.

Phentolamine Mesylate for Injection, USP is indicated for the prevention or treatment of dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine.

Phentolamine Mesylate for Injection, USP is also indicated for the diagnosis of pheochromocytoma by the Phentolamine Mesylate for Injection, USP blocking test.

Contraindications

Myocardial infarction, history of myocardial infarction, coronary insufficiency, angina or other evidence suggestive of coronary artery disease; hypersensitivity to Phe...